It is the first time in state history that this elevated toxin has prompted a recall, and has even led to the shutdown of harvesting for much of the northern coast.

The department said Tuesday that area stretches from Otter Point in Acadia all the way to the Canadian border.

"It's a big area. It's a big chunk of the coast so but again this is not something we're taking lightly. It's something we take very seriously. We want to ensure the health of the public and make sure we're taking these actions," Joe Nichols, spokesman for the Department of Marine Resources said.

It is due to what's called “amnesic shellfish poisoning” caused by elevated levels of a toxin that was found in routine testing for red tide.

"It's the concentration of the toxin. It's domoic acid is the name of the toxin," Nichols said.

The department says it has reached out to dealers to pull the shellfish, primarily clams and mussels, harvested in the area during the end of September.

"We do feel confident that we've taken all the appropriate steps between the recall and closure to ensure that we get impacted product out of the supply chain,” Nichols said.

If consumed, Nichols said the toxin could be extremely harmful.

"It's something that we take very seriously. It's something that can start out with gastrointestinal problems, and you experience those symptoms within 24 hours," Nichols said.

So far no illnesses have been reported, but Nichols said the toxin could even lead to neurological issues.

"We don't have any specific science or research at this point to tell us exactly why now and why this is happening here,” Nichols said.

The department says rigorous monitoring by the Public Health Bureau will continue in the area until it is safe to reopen.